In this paper, quantitative observations of dry granular flows subject to varying magnitude and direction of Coriolis acceleration are presented in order to assess the robustness of the Savage-Hutter shallow water approximation of granular flow for modelling landslides. Nine tests carried out at 708 and 458 slope inclinations are described for cases where no Coriolis acceleration was applied (i.e. tests performed at 1g), and where the Coriolis acceleration acted into or out of the slope (centrifuge tests). Given that the magnitude of the Coriolis term is velocity dependent, each point within a model landslide on the centrifuge experienced a unique time and space-varying magnitude of Coriolis acceleration, altering the flow displacement with time and final deposit characteristics. The resultant behaviour is compared to a depth-averaged flow model based on a frictional rheology. A single set of model parameters was found to be appropriate for all test conditions and directions/magnitudes of Coriolis acceleration, illustrating the robustness of the frictional depth-averaged approach to capture the mobility of dry granular flows, albeit as a 'Class C' type of prediction. It is noted that the empirically derived basal interface friction was found to be lower than the static interface friction determined by conventional testing, suggesting that new methods are needed for the a priori determination of suitable rheological parameters for high-speed flows.

In this paper a displacement-based design procedure is presented to rationally account for the effects of soil–foundation–structure interaction (SFSI) in the seismic design of shallow foundations. The non-linear deformations at the soil–foundation interface, such as foundation uplift, soil yield and soil–foundation shear deformation can dramatically alter the dynamic response of a building. The lack of consideration of the modifying factors of SFSI and an absence of procedures for controlling foundation and soil behaviour under seismic loads have resulted in inadequate designs for buildings sited on soft soil. A soil–foundation macro-element model was used to calibrate expressions to quantify the non-linear foundation rotational stiffness as well as the effects of foundation energy dissipation and soil–foundation shear deformation on the response of the soil–structure system. A series of concrete wall buildings were designed with the proposed design procedure and numerically assessed to validate the suitability of the design procedure. The simple hand calculation procedure presented here quantifies the modifying factors of SFSI in an intuitive and direct manner to allow engineers to design building–foundation systems with a clear understanding of their expected performance.

The time of liquefaction triggering during a strong ground motion can have a large influence on the expected level of foundation and superstructure damage. To enable simple, yet accurate estimates of the triggering time, the build-up of pore pressure needs to be understood in terms of cumulative measures of ground motion intensity. This paper develops a theoretical framework and simple procedure to predict the build-up of excess pore pressure based on the principles of conservation of energy. The liquefaction resistance is first quantified in terms of cumulative absolute change in strain energy, which is shown through the evaluation of experimental cyclic simple shear tests to be insensitive to loading amplitude. A ground motion intensity measure is presented that uniquely calculates the cumulative absolute change in kinetic energy. This intensity measure is then used to provide an exact analytical solution for the cumulative absolute change in strain energy at any depth in a homogenous linear elastic soil deposit using the novel, nodal surface energy spectrum (NSES). A simple reduction to the NSES is proposed for viscous and nonlinear soil deposits, as well as a correction for changes in stiffness between layers of soil. The estimation of strain energy and build-up of pore pressure using the simple NSES method was applied to 500 randomly generated soil deposits using a range of different ground motions and validated against nonlinear total stress and nonlinear effective stress time-history analyses, with the NSES method providing a high level of accuracy. The proposed spectrum based solution provides an efficient and physically consistent procedure for the prediction of excess pore pressure build-up.

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